<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <title>alert - Bootstrap</title>
    <link rel="stylesheet" href="css/bootstrap.min.css" />
        <style type="text/css" media="all">
            .container{margin-top:2em;}
        </style>
</head>

<body>

    <div class="container">
        <div class="alert alert-warning alert-dismissible" role="alert">
            <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
            <strong>Warning!</strong> Better check yourself, you're not looking too good.
        </div>
    </div>

    <script src="//cdn.bootcss.com/jquery/2.1.4/jquery.min.js"></script>
    <script src="js/bootstrap.min.js" type="text/javascript" charset="utf-8"></script>
    <script type="text/javascript" charset="utf-8">
    </script>
</body>

</html>
